nost: In a pump, I would recommend either the Remington 870 Police with magnum receiver (meaning it can handle the 3″ shells) or the Mossberg 590. I’d get it with rifle sights, so you can shoot slug loads and if you get the Mossberg, I’d get the ghost ring sights.
The Remmie has a smoother action than the Mossberg, which is rough IMO, but the Mossberg is cheaper.
I’d add a mag extension (that will give you an 8 round capacity), and a sling and you’re in business.